Process and installation for the conversion of crude oil to petrochemicals having an improved propylene yield

ABSTRACT

The present invention relates to an integrated process to convert crude oil into petrochemical products comprising crude oil distillation, aromatic ring opening, and olefins synthesis, which process comprises subjecting a hydrocarbon feed to aromatic ring opening to produce LPG and subjecting the LPG produced in the integrated process to olefins synthesis. Furthermore, the present invention relates to a process installation to convert crude oil into petrochemical products comprising a crude distillation unit comprising an inlet for crude oil and at least one outlet for kerosene and/or gasoil; an aromatic ring opening unit comprising an inlet for a hydrocarbon feed to aromatic ring opening and an outlet for LPG; and a unit for the olefins synthesis comprising an inlet for LPG produced by the integrated petrochemical process installation and an outlet for olefins. The hydrocarbon feed subjected to aromatic ring opening comprises kerosene and/or gasoil produced by crude oil distillation in the process; and refinery unit-derived middle-distillate produced in the process. The process and the process installation of the present invention have an increased production of petrochemicals at the expense of the production of fuels and an improved propylene yield.

The present invention relates to an integrated process to convert crudeoil into petrochemical products comprising crude oil distillation,aromatic ring opening, and olefins synthesis. Furthermore, the presentinvention relates to a process installation to convert crude oil intopetrochemical products comprising a crude distillation unit, a aromaticring opening unit and a unit for olefins synthesis.

It has been previously described that a crude oil refinery can beintegrated with downstream chemical plants such as a pyrolysis steamcracking unit in order to increase the production of high-valuechemicals at the expense of the production of fuels.

U.S. Pat. No. 3,702,292 describes an integrated crude oil refineryarrangement for producing fuel and chemical products, involving crudeoil distillation means, hydrocracking means, delayed coking means,reforming means, ethylene and propylene producing means comprising apyrolysis steam cracking unit and a pyrolysis products separation unit,catalytic cracking means, aromatic product recovery means, butadienerecovery means and alkylation means in an inter-related system toproduce a conversion of crude oil to petrochemicals of about 50% and aconversion of crude oil to fuels of about 50%.

A major drawback of conventional means and methods to integrate oilrefinery operations with downstream chemical plants to producepetrochemicals is that such integrated processes still producesignificant amounts of fuel. Furthermore, conventional means and methodsto integrate oil refinery operations with downstream chemical plantshave a relatively low propylene yield in terms of wt-% of crude.

It was an object of the present invention to provide a means and methodsto integrate oil refinery operations with downstream chemical plantswhich has an increased production of petrochemicals at the expense ofthe production of fuels. It was furthermore an object of the presentinvention to provide a means and methods to integrate oil refineryoperations with downstream chemical plants which has an improvedpropylene yield.

The solution to the above problem is achieved by providing theembodiments as described herein below and as characterized in theclaims.

In one aspect, the present invention relates to an integrated process toconvert crude oil into petrochemical products. This process is alsopresented in FIGS. 1-3 which are further described herein below.

Accordingly, the present invention provides an integrated process toconvert crude oil into petrochemical products comprising crude oildistillation, aromatic ring opening and olefins synthesis, which processcomprises subjecting a hydrocarbon feed to aromatic ring opening toproduce LPG and subjecting the LPG produced in the integrated process toolefins synthesis, wherein said hydrocarbon feed comprises:

-   -   kerosene and/or gasoil produced by crude oil distillation in the        process; and    -   refinery unit-derived middle-distillate produced in the process.

Conventionally, petrochemical products, such as propylene, are producedby subjecting crude oil to crude oil distillation and to subjectspecific crude oil fractions thus obtained to a refinery process. In thecontext of the present invention, it was found that the propylene yieldof a process to convert crude oil into petrochemical products can beimproved by subjecting one or more of naphtha, kerosene and gasoil toaromatic ring opening and subsequently converting the LPG produced byaromatic ring opening into olefins, when compared to subjecting the samecrude oil fractions directly to steam cracking. As used herein, the term“propylene yield” relates to the wt-% of propylene produced of the totalmass of the crude.

Furthermore, by first converting the hydrocarbon feedstock to LPG beforesubjecting to olefin synthesis, the fractionation section downstream ofthe olefin synthesis unit can be much less complex since much lessby-products, such as carbon black oil or cracked distillate, areproduced which leads to greatly reduced capital expenditures.

Accordingly, the term “kerosene and/or gasoil produced by crude oildistillation in the process” means that said one or more of kerosene andgasoil are produced by the crude distillation process step comprised inthe integrated process of the present invention. Moreover, the term“refinery unit-derived middle-distillate produced in the process” meansthat said refinery unit-derived middle-distillate are produced by arefinery unit process step comprised in the integrated process of thepresent invention.

The prior art describes processes for producing petrochemical productsfrom specific hydrocarbon feeds such as specific crude oil fractionsand/or refinery unit-derived distillates.

U.S. Pat. No. 3,839,484 describes a process for the preparation ofunsaturated hydrocarbons by pyrolysis of naphthas in a pyrolysis furnacecomprising hydrocracking said naphthas to form a mixture of paraffinsand isoparaffins said mixture consisting essentially of hydrocarbonscontaining from 1 to about 7 carbon atoms per molecule and pyrolyzingthe resulting mixture of paraffins and isoparaffins in said pyrolysisfurnace. The process of U.S. Pat. No. 3,839,484 further describes thatthe diesel fuel and distillate fuels boiling in the range of 400-650° F.(about 204-343° C.) are not further processed.

The term “crude oil” as used herein refers to the petroleum extractedfrom geologic formations in its unrefined form. The term crude oil willalso be understood to include that which has been subjected to water-oilseparations and/or gas-oil separation and/or desalting and/orstabilization. Any crude oil is suitable as the source material for theprocess of this invention, including Arabian Heavy, Arabian Light, otherGulf crudes, Brent, North Sea crudes, North and West African crudes,Indonesian, Chinese crudes and mixtures thereof, but also shale oil, tarsands, gas condensates and bio-based oils. The crude oil used as feed tothe process of the present invention preferably is conventionalpetroleum having an API gravity of more than 20° API as measured by theASTM D287 standard. More preferably, the crude oil used in the processof the present invention is a light crude oil having an API gravity ofmore than 30° API. Most preferably, the crude oil used in the process ofthe present invention comprises Arabian Light Crude Oil. Arabian LightCrude Oil typically has an API gravity of between 32-36° API and asulfur content of between 1.5-4.5 wt-%.

The term “petrochemicals” or “petrochemical products” as used hereinrelates to chemical products derived from crude oil that are not used asfuels. Petrochemical products include olefins and aromatics that areused as a basic feedstock for producing chemicals and polymers.High-value petrochemicals include olefins and aromatics. Typicalhigh-value olefins include, but are not limited to, ethylene, propylene,butadiene, butylene-1, isobutylene, isoprene, cyclopentadiene andstyrene. Typical high-value aromatics include, but are not limited to,benzene, toluene, xylene and ethyl benzene.

The term “fuels” as used herein relates to crude oil-derived productsused as energy carrier. Unlike petrochemicals, which are a collection ofwell-defined compounds, fuels typically are complex mixtures ofdifferent hydrocarbon compounds. Fuels commonly produced by oilrefineries include, but are not limited to, gasoline, jet fuel, dieselfuel, heavy fuel oil and petroleum coke.

The term “gases produced by the crude distillation unit” or “gasesfraction” as used herein refers to the fraction obtained in a crude oildistillation process that is gaseous at ambient temperatures.Accordingly, the “gases fraction” derived by crude distillation mainlycomprises C1-C4 hydrocarbons and may further comprise impurities such ashydrogen sulfide and carbon dioxide. In this specification, otherpetroleum fractions obtained by crude oil distillation are referred toas “naphtha”, “kerosene”, “gasoil” and “resid”. The terms naphtha,kerosene, gasoil and resid are used herein having their generallyaccepted meaning in the field of petroleum refinery processes; see Alfkeet al. (2007) Oil Refining, Ullmann's Encyclopedia of IndustrialChemistry and Speight (2005) Petroleum Refinery Processes, Kirk-OthmerEncyclopedia of Chemical Technology. In this respect, it is to be notedthat there may be overlap between the different crude oil distillationfractions due to the complex mixture of the hydrocarbon compoundscomprised in the crude oil and the technical limits to the crude oildistillation process. Preferably, the term “naphtha” as used hereinrelates to the petroleum fraction obtained by crude oil distillationhaving a boiling point range of about 20-200° C., more preferably ofabout 30-190° C. Preferably, light naphtha is the fraction having aboiling point range of about 20-100° C., more preferably of about 30-90°C. Heavy naphtha preferably has a boiling point range of about 80-200°C., more preferably of about 90-190° C. Preferably, the term “kerosene”as used herein relates to the petroleum fraction obtained by crude oildistillation having a boiling point range of about 180-270° C., morepreferably of about 190-260° C. Preferably, the term “gasoil” as usedherein relates to the petroleum fraction obtained by crude oildistillation having a boiling point range of about 250-360° C., morepreferably of about 260-350° C. Preferably, the term “resid” as usedherein relates to the petroleum fraction obtained by crude oildistillation having a boiling point of more than about 340° C., morepreferably of more than about 350° C.

As used herein, the term “refinery unit” relates to a section of apetrochemical plant complex for the chemical conversion of crude oil topetrochemicals and fuels. In this respect, it is to be noted that a unitfor olefins synthesis, such as a steam cracker, is also considered torepresent a “refinery unit”. In this specification, differenthydrocarbons streams produced by refinery units or produced in refineryunit operations are referred to as: refinery unit-derived gases,refinery unit-derived light-distillate, refinery unit-derivedmiddle-distillate and refinery unit-derived heavy-distillate.Accordingly, a refinery unit derived distillate is obtained as theresult of a chemical conversion followed by a separation, e.g. bydistillation or by extraction, which is in contrast to a crude oilfraction. The term “refinery unit-derived gases” relates to the fractionof the products produced in a refinery unit that is gaseous at ambienttemperatures. Accordingly, the refinery unit-derived gas stream maycomprise gaseous compounds such as LPG and methane. Other componentscomprised in the refiner unit-derived gas stream may be hydrogen andhydrogen sulfide. The terms light-distillate, middle-distillate andheavy-distillate are used herein having their generally accepted meaningin the field of petroleum refinery processes; see Speight, J. G. (2005)loc.cit. In this respect, it is to be noted that there may be overlapbetween different distillation fractions due to the complex mixture ofthe hydrocarbon compounds comprised in the product stream produced byrefinery unit operations and the technical limits to the distillationprocess used to separate the different fractions. Preferably, therefinery-unit derived light-distillate is the hydrocarbon distillateobtained in a refinery unit process having a boiling point range ofabout 20-200° C., more preferably of about 30-190° C. The“light-distillate” is often relatively rich in aromatic hydrocarbonshaving one aromatic ring. Preferably, the refinery-unit derivedmiddle-distillate is the hydrocarbon distillate obtained in a refineryunit process having a boiling point range of about 180-360° C., morepreferably of about 190-350° C. The “middle-distillate” is relativelyrich in aromatic hydrocarbons having two aromatic rings. Preferably, therefinery-unit derived heavy-distillate is the hydrocarbon distillateobtained in a refinery unit process having a boiling point of more thanabout 340° C., more preferably of more than about 350° C. The“heavy-distillate” is relatively rich in hydrocarbons having condensedaromatic rings.

The term “aromatic hydrocarbons” or “aromatics” is very well known inthe art. Accordingly, the term “aromatic hydrocarbon” relates tocyclically conjugated hydrocarbon with a stability (due todelocalization) that is significantly greater than that of ahypothetical localized structure (e.g. Kekulé structure). The mostcommon method for determining aromaticity of a given hydrocarbon is theobservation of diatropicity in the 1H NMR spectrum, for example thepresence of chemical shifts in the range of from 7.2 to 7.3 ppm forbenzene ring protons.

The terms “naphthenic hydrocarbons” or “naphthenes” or “cycloalkanes” isused herein having its established meaning and accordingly relates totypes of alkanes that have one or more rings of carbon atoms in thechemical structure of their molecules.

The term “olefin” is used herein having its well-established meaning.Accordingly, olefin relates to an unsaturated hydrocarbon compoundcontaining at least one carbon-carbon double bond. Preferably, the term“olefins” relates to a mixture comprising two or more of ethylene,propylene, butadiene, butylene-1, isobutylene, isoprene andcyclopentadiene.

One of the petrochemical products produced in the process of the presentinvention is BTX. The term “LPG” as used herein refers to thewell-established acronym for the term “liquefied petroleum gas”. LPGgenerally consists of a blend of C2-C4 hydrocarbons i.e. a mixture ofC2, C3, and C4 hydrocarbons. Preferably, the product produced in theprocess of the present invention comprises further useful aromatichydrocarbons such as ethylbenzene. Accordingly, the present inventionpreferably provides a process for producing a mixture of benzene,toluene xylenes and ethylbenzene (“BTXE”). The product as produced maybe a physical mixture of the different aromatic hydrocarbons or may bedirectly subjected to further separation, e.g. by distillation, toprovide different purified product streams. Such purified product streammay include a benzene product stream, a toluene product stream, a xyleneproduct stream and/or an ethylbenzene product stream.

The term “BTX” as used herein relates to a mixture of benzene, tolueneand xylenes.

As used herein, the term “C# hydrocarbons”, wherein “#” is a positiveinteger, is meant to describe all hydrocarbons having # carbon atoms.Moreover, the term “C#+ hydrocarbons” is meant to describe allhydrocarbon molecules having # or more carbon atoms. Accordingly, theterm “C5+ hydrocarbons” is meant to describe a mixture of hydrocarbonshaving 5 or more carbon atoms. The term “C5+ alkanes” accordinglyrelates to alkanes having 5 or more carbon atoms.

The process of the present invention involves crude distillation, whichcomprises separating different crude oil fractions based on a differencein boiling point. As used herein, the term “crude distillation unit” or“crude oil distillation unit” relates to the fractionating column thatis used to separate crude oil into fractions by fractional distillation;see Alfke et al. (2007) loc.cit. Preferably, the crude oil is processedin an atmospheric distillation unit to separate gas oil and lighterfractions from higher boiling components (atmospheric residuum or“resid”). In the present invention, it is not required to pass the residto a vacuum distillation unit for further fractionation of the resid,and it is possible to process the resid as a single fraction. In case ofrelatively heavy crude oil feeds, however, it may be advantageous tofurther fractionate the resid using a vacuum distillation unit tofurther separate the resid into a vacuum gas oil fraction and vacuumresidue fraction. In case vacuum distillation is used, the vacuum gasoil fraction and vacuum residue fraction may be processed separately inthe subsequent refinery units. For instance, the vacuum residue fractionmay be specifically subjected to solvent deasphalting before furtherprocessing. Preferably, the term “vacuum gas oil” as used herein relatesto the petroleum fraction obtained by crude oil distillation having ahaving a boiling point range of about 340-560° C., more preferably ofabout 350-550° C. Preferably, the term “vacuum resid” as used hereinrelates to the petroleum fraction obtained by crude oil distillationhaving a boiling point of more than about 540° C., more preferably ofmore than about 550° C.

The “aromatic ring opening unit” refers to a refinery unit wherein thearomatic ring opening process is performed. Aromatic ring opening is aspecific hydrocracking process that is particularly suitable forconverting a feed that is relatively rich in aromatic hydrocarbon havinga boiling point in the kerosene and gasoil boiling point range, andoptionally the vacuum gasoil boiling point range, to produce LPG and,depending on the specific process and/or process conditions, alight-distillate (ARO-derived gasoline). Such an aromatic ring openingprocess (ARO process) is for instance described in U.S. Pat. No.3,256,176 and U.S. Pat. No. 4,789,457. Such processes may comprise ofeither a single fixed bed catalytic reactor or two such reactors inseries together with one or more fractionation units to separate desiredproducts from unconverted material and may also incorporate the abilityto recycle unconverted material to one or both of the reactors. Reactorsmay be operated at a temperature of 200-600° C., preferably 300-400° C.,a pressure of 3-35 MPa, preferably 5 to 20 MPa together with 5-20 wt-%of hydrogen (in relation to the hydrocarbon feedstock), wherein saidhydrogen may flow co-current with the hydrocarbon feedstock or countercurrent to the direction of flow of the hydrocarbon feedstock, in thepresence of a dual functional catalyst active for bothhydrogenation-dehydrogenation and ring cleavage, wherein said aromaticring saturation and ring cleavage may be performed. Catalysts used insuch processes comprise one or more elements selected from the groupconsisting of Pd, Rh, Ru, Ir, Os, Cu, Co, Ni, Pt, Fe, Zn, Ga, In, Mo, Wand V in metallic or metal sulphide form supported on an acidic solidsuch as alumina, silica, alumina-silica and zeolites. In this respect,it is to be noted that the term “supported on” as used herein includesany conventional way to provide a catalyst which combines one or moreelements with a catalytic support. By adapting either single or incombination the catalyst composition, operating temperature, operatingspace velocity and/or hydrogen partial pressure, the process can besteered towards full saturation and subsequent cleavage of all rings ortowards keeping one aromatic ring unsaturated and subsequent cleavage ofall but one ring. In the latter case, the ARO process produces alight-distillate (“ARO-gasoline”) which is relatively rich inhydrocarbon compounds having one aromatic and or naphthenic ring. In thecontext of the present invention, it is preferred to use an aromaticring opening process that is optimized to open all aromatic rings andthus to produce LPG at the expense of a light-distillate which isrelatively rich in hydrocarbon compounds having one aromatic ring. Yet,also in a mode wherein all aromatic rings are opened, the ARO processmay still produce small amounts of distillates, which are preferablyrecycled to refinery units capable of processing and upgrading saiddistillates to petrochemicals or to intermediate products that can befurther upgraded to petrochemicals. A further aromatic ring openingprocess (ARO process) is described in U.S. Pat. No. 7,513,988.Accordingly, the ARO process may comprise aromatic ring saturation at atemperature of 100-500° C., preferably 200-500° C., more preferably300-500° C., a pressure of 2-10 MPa together with 5-30 wt-%, preferably10-30 wt-% of hydrogen (in relation to the hydrocarbon feedstock) in thepresence of an aromatic hydrogenation catalyst and ring cleavage at atemperature of 200-600° C., preferably 300-400° C., a pressure of 1-12MPa together with 5-20 wt-% of hydrogen (in relation to the hydrocarbonfeedstock) in the presence of a ring cleavage catalyst, wherein saidaromatic ring saturation and ring cleavage may be performed in onereactor or in two consecutive reactors. The aromatic hydrogenationcatalyst may be a conventional hydrogenation/hydrotreating catalyst suchas a catalyst comprising a mixture of Ni, W and Mo on a refractorysupport, typically alumina. The ring cleavage catalyst comprises atransition metal or metal sulphide component and a support. Preferablythe catalyst comprises one or more elements selected from the groupconsisting of Pd, Rh, Ru, Ir, Os, Cu, Co, Ni, Pt, Fe, Zn, Ga, In, Mo, Wand V in metallic or metal sulphide form supported on an acidic solidsuch as alumina, silica, alumina-silica and zeolites. By adapting eithersingle or in combination the catalyst composition, operatingtemperature, operating space velocity and/or hydrogen partial pressure,the process can be steered towards full saturation and subsequentcleavage of all rings or towards keeping one aromatic ring unsaturatedand subsequent cleavage of all but one ring. In the latter case, the AROprocess produces a light-distillate (“ARO-gasoline”) which is relativelyrich in hydrocarbon compounds having one aromatic ring. In the contextof the present invention, it is preferred to use an aromatic ringopening process that is optimized to open all aromatic rings and thus toproduce LPG at the expense of a light-distillate which is relativelyrich in hydrocarbon compounds having one aromatic ring. Yet, also in amode wherein all aromatic rings are opened, the ARO process may stillproduce small amounts of distillates, which are preferably recycled torefinery units capable of processing and upgrading said distillates topetrochemicals or to intermediate products that can be further upgradedto petrochemicals. Other examples of aromatic ring opening processes toproduce LPG are described in U.S. Pat. No. 7,067,448 and US2005/0101814.

By steering the aromatic ring opening process towards full saturationand subsequent cleavage of all rings or towards keeping one aromaticring unsaturated and subsequent cleavage of all but one ring, the ratioof olefins produced and aromatics produced in the process of the presentinvention can be steered so that a neutral hydrogen balance can beobtained, depending on hydrogen balance of the feed. With hydrogen-richfeeds, such as shale oil, (almost) no aromatics have to be produced toobtain hydrogen balanced overall process.

The hydrocarbon feed to aromatic ring opening used in the process of thepresent invention preferably comprises kerosene and gasoil produced bycrude oil distillation in the process and refinery unit-derivedmiddle-distillate produced in the process.

More preferably, the hydrocarbon feed to aromatic ring opening used inthe process of the present invention comprises naphtha, kerosene andgasoil produced by crude oil distillation in the process and refineryunit-derived light-distillate and refinery unit-derivedmiddle-distillate produced in the process.

The LPG produced in the process that is subjected to olefins synthesispreferably comprises LPG comprised in the gases fraction derived bycrude oil distillation and LPG comprised in the refinery unit-derivedgases.

Preferably, the process of the present invention comprises:

-   (a) subjecting crude oil to crude oil distillation to produce gases    fraction, resid and one or more of kerosene and gasoil;-   (b) subjecting resid to resid upgrading to produce LPG and a liquid    resid upgrading effluent;-   (c) subjecting liquid resid upgrading effluent and one or more    selected from the group consisting of kerosene and gasoil to    aromatic ring opening to produce LPG; and-   (d) subjecting LPG produced in the integrated process to olefins    synthesis.

By specifically subjecting resid to resid upgrading to produce LPG and aliquid resid upgrading effluent and by subjecting said liquid residupgrading effluent to aromatic ring opening, the propylene yield or theprocess of the present invention can be further improved. Furthermore,the crude oil can be upgraded to petrochemical products, particularlypropylene, to a much greater extent.

As used herein, the term “resid upgrading unit” relates to a refineryunit suitable for the process of resid upgrading, which is a process forbreaking the hydrocarbons comprised in the resid and/or refineryunit-derived heavy-distillate into lower boiling point hydrocarbons; seeAlfke et al. (2007) loc.cit. Commercially available technologies includea delayed coker, a fluid coker, a resid FCC, a Flexicoker, a visbreakeror a catalytic hydrovisbreaker. Preferably, the resid upgrading unit maybe a coking unit or a resid hydrocracker. A “coking unit” is an oilrefinery processing unit that converts resid into LPG, light-distillate,middle-distillate, heavy-distillate and petroleum coke. The processthermally cracks the long chain hydrocarbon molecules in the residualoil feed into shorter chain molecules.

The feed to resid upgrading preferably comprises resid andheavy-distillate produced in the process. Such heavy-distillate maycomprise the heavy-distillate produced by a steam cracker, such ascarbon black oil and/or cracked distillate but may also comprise theheavy-distillate produced by resid upgrading, which may be recycled toextinction. Yet, a relatively small pitch stream may be purged from theprocess.

Preferably, the resid upgrading used in the process of the presentinvention is resid hydrocracking.

By selecting resid hydrocracking over other means for resid upgrading,the propylene yield and the carbon efficiency of the process of thepresent invention can be further improved.

A “resid hydrocracker” is an oil refinery processing unit that issuitable for the process of resid hydrocracking, which is a process toconvert resid into LPG, light distillate, middle-distillate andheavy-distillate. Resid hydrocracking processes are well known in theart; see e.g. Alfke et al. (2007) loc.cit. Accordingly, 3 basic reactortypes are employed in commercial hydrocracking which are a fixed bed(trickle bed) reactor type, an ebullated bed reactor type and slurry(entrained flow) reactor type. Fixed bed resid hydrocracking processesare well-established and are capable of processing contaminated streamssuch as atmospheric residues and vacuum residues to produce light- andmiddle-distillate which can be further processed to produce olefins andaromatics. The catalysts used in fixed bed resid hydrocracking processescommonly comprise one or more elements selected from the groupconsisting of Co, Mo and Ni on a refractory support, typically alumina.In case of highly contaminated feeds, the catalyst in fixed bed residhydrocracking processes may also be replenished to a certain extend(moving bed). The process conditions commonly comprise a temperature of350-450° C. and a pressure of 2-20 MPa gauge. Ebullated bed residhydrocracking processes are also well-established and are inter aliacharacterized in that the catalyst is continuously replaced allowing theprocessing of highly contaminated feeds. The catalysts used in ebullatedbed resid hydrocracking processes commonly comprise one or more elementsselected from the group consisting of Co, Mo and Ni on a refractorysupport, typically alumina. The small particle size of the catalystsemployed effectively increases their activity (c.f. similar formulationsin forms suitable for fixed bed applications). These two factors allowebullated bed hydrocracking processes to achieve significantly higheryields of light products and higher levels of hydrogen addition whencompared to fixed bed hydrocracking units. The process conditionscommonly comprise a temperature of 350-450° C. and a pressure of 5-25MPa gauge. Slurry resid hydrocracking processes represent a combinationof thermal cracking and catalytic hydrogenation to achieve high yieldsof distillable products from highly contaminated resid feeds. In thefirst liquid stage, thermal cracking and hydrocracking reactions occursimultaneously in the fluidized bed at process conditions that include atemperature of 400-500° C. and a pressure of 15-25 MPa gauge. Resid,hydrogen and catalyst are introduced at the bottom of the reactor and afluidized bed is formed, the height of which depends on flow rate anddesired conversion. In these processes catalyst is continuously replacedto achieve consistent conversion levels through an operating cycle. Thecatalyst may be an unsupported metal sulfide that is generated in situwithin the reactor. In practice the additional costs associated with theebullated bed and slurry phase reactors are only justified when a highconversion of highly contaminated heavy streams such as vacuum gas oilsis required. Under these circumstances the limited conversion of verylarge molecules and the difficulties associated with catalystdeactivation make fixed bed processes relatively unattractive in theprocess of the present invention. Accordingly, ebullated bed and slurryreactor types are preferred due to their improved yield of light- andmiddle-distillate when compared to fixed bed hydrocracking. As usedherein, the term “resid upgrading liquid effluent” relates to theproduct produced by resid upgrading excluding the gaseous products, suchas methane and LPG and the heavy distillate produced by resid upgrading.The heavy-distillate produced by resid upgrading is preferably recycledto the resid upgrading unit until extinction. However, it may benecessary to purge a relatively small pitch stream. From the viewpointof carbon efficiency, a resid hydrocracker is preferred over a cokingunit as the latter produces considerable amounts of petroleum coke thatcannot be upgraded to high value petrochemical products. From theviewpoint of the hydrogen balance of the integrated process, it may bepreferred to select a coking unit over a resid hydrocracker as thelatter consumes considerable amounts of hydrogen. Also in view of thecapital expenditure and/or the operating costs it may be advantageous toselect a coking unit over a resid hydrocracker.

In case the resid is further fractionated using a vacuum distillationunit to separate the resid into a vacuum gas oil fraction and vacuumresidue fraction, it is preferred to subject the vacuum gasoil to vacuumgasoil hydrocracking and the vacuum resid to vacuum resid hydrocracking,wherein the heavy distillate produced by vacuum resid hydrocracking issubsequently subjected to vacuum gasoil hydrocracking. In case thepresent invention involves vacuum distillation, the vacuum gasoil thusobtained is preferably fed to the aromatic ring opening unit togetherwith one or more other hydrocarbon streams that are relatively rich inaromatic hydrocarbons and which have a boiling point in the kerosene andgasoil boiling point range. Such hydrocarbon streams that are relativelyrich in aromatic hydrocarbons and which have a boiling point in thekerosene and gasoil boiling point range may be selected from the groupconsisting of kerosene, gasoil and middle-distillate. The vacuum residuehydrocracking preferably is slurry resid hydrocracking as defined hereinabove.

Preferably at least 50 wt-%, more preferably at least 60 wt-%, even morepreferably at least 70 wt-%, particularly preferably at least 80 wt-%,more particularly preferably at least 90 wt-% and most preferably atleast 95 wt-% of the combined kerosene and gasoil produced by the crudeoil distillation in the process is subjected to hydrocracking.Accordingly, preferably less than 50 wt-%, more preferably less than 40wt-%, even more preferably less than 30 wt-%, particularly preferablyless than 20 wt-%, more particularly preferably less than 10 wt-% andmost preferably less 5 wt-% of the crude oil is converted into fuels inthe process of the present invention.

As used herein, the term “unit for olefins synthesis” relates to a unitwherein a process for olefins synthesis is performed. This term includesany process for the conversion of hydrocarbons to olefins including, butnot limited to non-catalytic processes such as pyrolysis or steamcracking, catalytic processes such as propane dehydrogenation or butanedehydrogenation, and combinations of the two such as catalytic steamcracking.

A very common process for olefins synthesis involves “pyrolysis” or“steam cracking”. As used herein, the term “steam cracking” relates to apetrochemical process in which saturated hydrocarbons are broken downinto smaller, often unsaturated, hydrocarbons such as ethylene andpropylene. In steam cracking gaseous hydrocarbon feeds like ethane,propane and butanes, or mixtures thereof, (gas cracking) or liquidhydrocarbon feeds like naphtha or gasoil (liquid cracking) is dilutedwith steam and briefly heated in a furnace without the presence ofoxygen. Typically, the reaction temperature is 750-900° C. and thereaction is only allowed to take place very briefly, usually withresidence times of 50-1000 milliseconds. Preferably, a relatively lowprocess pressure is to be selected of atmospheric up to 175 kPa gauge.Preferably, the hydrocarbon compounds ethane, propane and butanes areseparately cracked in accordingly specialized furnaces to ensurecracking at optimal conditions. After the cracking temperature has beenreached, the gas is quickly quenched to stop the reaction in a transferline heat exchanger or inside a quenching header using quench oil. Steamcracking results in the slow deposition of coke, a form of carbon, onthe reactor walls. Decoking requires the furnace to be isolated from theprocess and then a flow of steam or a steam/air mixture is passedthrough the furnace coils. This converts the hard solid carbon layer tocarbon monoxide and carbon dioxide. Once this reaction is complete, thefurnace is returned to service. The products produced by steam crackingdepend on the composition of the feed, the hydrocarbon to steam ratioand on the cracking temperature and furnace residence time. Lighthydrocarbon feeds such as ethane, propane, butane or light naphtha giveproduct streams rich in the lighter polymer grade olefins, includingethylene, propylene, and butadiene. Heavier hydrocarbon (full range andheavy naphtha and gas oil fractions) also give products rich in aromatichydrocarbons.

To separate the different hydrocarbon compounds produced by steamcracking the cracked gas is subjected to a fractionation unit. Suchfractionation units are well known in the art and may comprise aso-called gasoline fractionator where the heavy-distillate (“carbonblack oil”) and the middle-distillate (“cracked distillate”) areseparated from the light-distillate and the gases. In the subsequentoptional quench tower, most of the light-distillate produced by steamcracking (“pyrolysis gasoline” or “pygas”) may be separated from thegases by condensing the light-distillate. Subsequently, the gases may besubjected to multiple compression stages wherein the remainder of thelight distillate may be separated from the gases between the compressionstages. Also acid gases (CO₂ and H₂S) may be removed between compressionstages. In a following step, the gases produced by pyrolysis may bepartially condensed over stages of a cascade refrigeration system toabout where only the hydrogen remains in the gaseous phase. Thedifferent hydrocarbon compounds may subsequently be separated by simpledistillation, wherein the ethylene, propylene and C4 olefins are themost important high-value chemicals produced by steam cracking. Themethane produced by steam cracking is generally used as fuel gas, thehydrogen may be separated and recycled to processes that consumehydrogen, such as hydrocracking processes. The acetylene produced bysteam cracking preferably is selectively hydrogenated to ethylene. Thealkanes comprised in the cracked gas may be recycled to the process forolefin synthesis.

Preferably, the olefins synthesis as used in the present inventioncomprises pyrolysis of ethane and dehydrogenation of propane. Byconverting one or more of naphtha, kerosene and gasoil produced by crudeoil distillation in the process; and refinery unit-derivedlight-distillate and/or refinery unit-derived middle-distillate producedin the process to LPG, the propane comprised in the LPG can be subjectedto propane dehydrogenation to produce propylene and hydrogen, which hasan improved propylene yield when compared to pyrolysis since in apropane dehydrogenation process substantially no undesired by-productsare produced.

By selecting olefins synthesis comprising propane dehydrogenation, theoverall hydrogen balance of the integrated process can be improved. Afurther advantage of integrating dehydrogenation process into theintegrated process is that a high-purity hydrogen stream is produced,which can be used as feed to aromatic ring opening or other upstreamrefinery processes without expensive purification.

The term “propane dehydrogenation unit” as used herein relates to apetrochemical process unit wherein a propane feedstream is convertedinto a product comprising propylene and hydrogen. Accordingly, the term“butane dehydrogenation unit” relates to a process unit for converting abutane feedstream into C4 olefins. Together, processes for thedehydrogenation of lower alkanes such as propane and butanes aredescribed as lower alkane dehydrogenation process. Processes for thedehydrogenation of lower alkanes are well-known in the art and includeoxidative dehydrogenation processes and non-oxidative dehydrogenationprocesses. In an oxidative dehydrogenation process, the process heat isprovided by partial oxidation of the lower alkane(s) in the feed. In anon-oxidative dehydrogenation process, which is preferred in the contextof the present invention, the process heat for the endothermicdehydrogenation reaction is provided by external heat sources such ashot flue gases obtained by burning of fuel gas or steam. In anon-oxidative dehydrogenation process the process conditions generallycomprise a temperature of 540-700° C. and an absolute pressure of 25-500kPa. For instance, the UOP Oleflex process allows for thedehydrogenation of propane to form propylene and of (iso)butane to form(iso)butylene (or mixtures thereof) in the presence of a catalystcontaining platinum supported on alumina in a moving bed reactor; seee.g. U.S. Pat. No. 4,827,072. The Uhde STAR process allows for thedehydrogenation of propane to form propylene or of butane to formbutylene in the presence of a promoted platinum catalyst supported on azinc-alumina spinel; see e.g. U.S. Pat. No. 4,926,005. The STAR processhas been recently improved by applying the principle ofoxydehydrogenation. In a secondary adiabatic zone in the reactor part ofthe hydrogen from the intermediate product is selectively converted withadded oxygen to form water. This shifts the thermodynamic equilibrium tohigher conversion and achieves a higher yield. Also the external heatrequired for the endothermic dehydrogenation reaction is partly suppliedby the exothermic hydrogen conversion. The Lummus Catofin processemploys a number of fixed bed reactors operating on a cyclical basis.The catalyst is activated alumina impregnated with 18-20 wt-% chromium;see e.g. EP 0 192 059 A1 and GB 2 162 082 A. The Catofin process has theadvantage that it is capable of handling impurities which would poison aplatinum catalyst. The products produced by a butane dehydrogenationprocess depend on the nature of the butane feed and the butanedehydrogenation process used. Also the Catofin process allows for thedehydrogenation of butane to form butylene; see e.g. U.S. Pat. No.7,622,623.

Preferably, the gases fraction produced by the crude distillation unitand the refinery unit-derived gases are subjected to gas separation toseparate the different components, for instance to separate methane fromLPG.

As used herein, the term “gas separation unit” relates to the refineryunit that separates different compounds comprised in the gases producedby the crude distillation unit and/or refinery unit-derived gases.Compounds that may be separated to separate streams in the gasseparation unit comprise ethane, propane, butanes, hydrogen and fuel gasmainly comprising methane. Any conventional method suitable for theseparation of said gases may be employed in the context of the presentinvention. Accordingly, the gases may be subjected to multiplecompression stages wherein acid gases such as CO₂ and H₂S may be removedbetween compression stages. In a following step, the gases produced maybe partially condensed over stages of a cascade refrigeration system toabout where only the hydrogen remains in the gaseous phase. Thedifferent hydrocarbon compounds may subsequently be separated bydistillation.

Preferably, the olefins synthesis as used in the present inventioncomprises pyrolysis of butanes. By selecting pyrolysis of butanes over,e.g. dehydrogenation of butanes, the propylene yield of the process ofthe present invention can be further improved.

Preferably, the process of the present invention further comprisessubjecting part of the liquid resid upgrading effluent, and optionallylight-distillate produced by aromatic ring opening, to fluid catalyticcracking to produce light-distillate, middle-distillate and olefins, andsubjecting said middle-distillate produced by fluid catalytic crackingto aromatic ring opening.

By subjecting the liquid resid upgrading effluent to fluid catalyticcracking, the hydrogen consumption of the process of the presentinvention can be reduced when compared to a process wherein theheavy-distillate produced by resid upgrading is recycled to said residupgrading to extinction. Furthermore, by selecting a process comprisingfluid catalytic cracking, the light-distillate produced by aromatic ringopening can be more efficiently upgraded to petrochemical products.

As used herein, the term “fluid catalytic cracker unit” or “FCC unit”relates to a refinery unit to convert high-boiling, high-molecularweight hydrocarbon fractions of petroleum crude oils to lower boilingpoint hydrocarbon fractions and olefinic gases. In a FCC unit, crackingtakes place generally using a very active zeolite-based catalyst in ashort-contact time vertical or upward-sloped pipe called the “riser”.Pre-heated feed is sprayed into the base of the riser via feed nozzleswhere it contacts extremely hot fluidized catalyst. Preferred processconditions used for fluid catalytic cracking generally include atemperature of 425-700° C. and a pressure of 10-800 kPa gauge. The hotcatalyst vaporizes the feed and catalyzes the cracking reactions thatbreak down the high-molecular weight hydrocarbons into lightercomponents including LPG, light-distillate and middle-distillate. Thecatalyst/hydrocarbon mixture flows upward through the riser for a fewseconds, and then the mixture is separated via cyclones. Thecatalyst-free hydrocarbons are routed to a main fractionator (acomponent of the FCC unit for separation into fuel gas, LPG, lightdistillate, middle distillate and heavy-distillate). “Spent” catalyst isdisengaged from the cracked hydrocarbon vapors and sent to a stripperwhere it is contacted with steam to remove hydrocarbons remaining in thecatalyst pores. The “spent” catalyst then flows into a fluidized-bedregenerator where air (or in some cases air plus oxygen) is used to burnoff the coke to restore catalyst activity and also provide the necessaryheat for the next reaction cycle, cracking being an endothermicreaction. The “regenerated” catalyst then flows to the base of theriser, repeating the cycle. The process of the present invention maycomprise several FCC units operated at different process conditions,depending on the hydrocarbon feed and the desired product slate. As usedherein, the term “low-severity FCC” or “refinery FCC” relates to a FCCprocess that is optimized towards the production of light-distillatethat is relatively rich in aromatics (“FCC-gasoline”). As mostconventional refineries are optimized towards gasoline production,conventional FCC process operating conditions can be considered torepresent low-severity FCC. Preferred process conditions used forrefinery FCC generally include a temperature of 425-570° C. and apressure of 10-800 kPa gauge. As used herein, the term “high-severityFCC” or “petrochemicals FCC” relates to a FCC process that is optimizedtowards the production of olefins. High-severity FCC processes are knownfrom the prior art and are inter alia described in EP 0 909 804 A2, EP 0909 582 A1 and U.S. Pat. No. 5,846,402. Preferred process conditionsused for high-severity FCC generally include a temperature of 540-700°C. and a pressure of 10-800 kPa gauge. In the present invention ahigh-severity FCC is preferred.

The process of the present invention may require removal of sulfur fromcertain crude oil fractions to prevent catalyst deactivation indownstream refinery processes, such as catalytic reforming or fluidcatalytic cracking. Such a hydrodesulfurization process is performed ina “HDS unit” or “hydrotreater”; see Alfke (2007) loc. cit. Generally,the hydrodesulfurization reaction takes place in a fixed-bed reactor atelevated temperatures of 200-425° C., preferably of 300-400° C. andelevated pressures of 1-20 MPa gauge, preferably 1-13 MPa gauge in thepresence of a catalyst comprising elements selected from the groupconsisting of Ni, Mo, Co, W and Pt, with or without promoters, supportedon alumina, wherein the catalyst is in a sulfide form.

Furthermore, the propylene yield can be further improved by convertingbutenes and ethylene produced in the process of the present invention topropylene using the methathesis process. The metathesis process is wellknown in the art and is inter alia described in U.S. Pat. No. 4,575,575.

In a further aspect, the invention also relates to a processinstallation suitable for performing the process of the invention. Thisprocess installation and the process as performed in said processinstallation is presented in FIGS. 1-3 (FIG. 1-3).

Accordingly, the present invention further provides a processinstallation to convert crude oil into petrochemical products comprising

a crude distillation unit (10) comprising an inlet for crude oil (100)and at least one outlet for kerosene and/or gasoil (310);an aromatic ring opening unit (26) comprising an inlet for a hydrocarbonfeed to aromatic ring opening (302) and an outlet for LPG (222); anda unit for the olefins synthesis (30) comprising an inlet for LPGproduced by the integrated petrochemical process installation (200) andan outlet for olefins (500),wherein said hydrocarbon feed to aromatic ring opening comprises:

-   -   kerosene and/or gasoil produced by the crude oil distillation        unit (10); and refinery unit-derived middle-distillate produced        the integrated petrochemical process installation.

This aspect of the present invention is presented in FIG. 1 (FIG. 1).

The crude distillation unit (10) preferably further comprises an outletfor the gases fraction (230). The LPG produced by aromatic ring opening(222) and LPG comprised in the gases fraction and refinery unit-derivedLPG produced in the integrated process (220) may be combined to form theinlet for LPG produced by the integrated petrochemical processinstallation (200). The crude distillation unit (10) preferably furthercomprises an outlet for the naphtha fraction. The naphtha produced bythe crude distillation unit may be combined with the kerosene and/or thegasoil produced by the crude oil distillation unit and subsequentlysubjected to aromatic ring opening. Furthermore, kerosene and/or gasoil,and optionally the naphtha, produced by the crude oil distillation unit(310) may be combined with refinery unit-derived middle-distillate andoptionally the refinery unit-derived light-distillate produced theintegrated petrochemical process installation (320) to form the inletfor a hydrocarbon feed to aromatic ring opening (302).

As used herein, the term “an inlet for X” or “an outlet of X”, wherein“X” is a given hydrocarbon fraction or the like relates to an inlet oroutlet for a stream comprising said hydrocarbon fraction or the like. Incase of an outlet for X is directly connected to a downstream refineryunit comprising an inlet for X, said direct connection may comprisefurther units such as heat exchangers, separation and/or purificationunits to remove undesired compounds comprised in said stream and thelike.

If, in the context of the present invention, a refinery unit is fed withmore than one feed stream, said feed streams may be combined to form onesingle inlet into the refinery unit or may form separate inlets to therefinery unit.

Furthermore, the crude distillation unit (10) may comprise an outlet forresid (400). The process installation of the present invention mayfurther comprise a resid upgrading unit (40) comprising an inlet forresid (400) and refinery unit-derived heavy-distillate (401), an outletfor LPG produced by resid upgrading (223) and an outlet for liquid residupgrading effluent (326). This aspect of the present invention ispresented in FIG. 2 (FIG. 2). The liquid resid upgrading effluent (326)comprises light-distillate and middle-distillate that preferably issubjected to aromatic ring opening.

The process installation of the present invention may further comprise afluid catalytic cracking unit (60) comprising an inlet for a part of theliquid resid upgrading effluent (326) and optionally light-distillateproduced by aromatic ring opening (328) and an outlet formiddle-distillate, and optionally light-distillate, produced by fluidcatalytic cracking (324) and olefins produced by fluid catalyticcracking (540). This aspect of the present invention is presented inFIG. 2 (FIG. 2).

The fluid catalytic cracking unit (60) may further comprise an outletfor methane (720). Furthermore, the process installation comprising afluid catalytic cracking unit (60) may comprise an outlet for the partof the liquid resid upgrading effluent that is not subjected to fluidcatalytic cracking (327), which may be recycled to the resid upgradingunit (40). In case part of the light-distillate produced by aromaticring opening is subjected to fluid catalytic cracking, the processinstallation unit comprises a aromatic ring opening unit (26) having anoutlet for light-distillate (328) which is combined with for a part ofthe liquid resid upgrading effluent (326). The fluid catalytic crackingunit (60) may further comprise an outlet for heavy-distillate producedfluid catalytic cracking (410) which may be recycled to the residupgrading unit (40) to further upgrade said heavy-distillate; see alsoFIG. 3.

Preferably, the process installation of the present invention furthercomprises: a gas separation unit (50) comprising an inlet for gasesproduced in the integrated process (200), an outlet for ethane (240) andan outlet for propane (250); an ethane cracker (31) comprising an inletfor ethane (240) and an outlet for ethylene (510); and

a propane dehydrogenation unit (32) comprising an inlet for propane(250) and an outlet for propylene (520). This aspect of the presentinvention is presented in FIG. 3 (FIG. 3).

The gas separation unit (50) may further comprise an outlet for methane(701). The ethane cracker (31) may further comprise an outlet forhydrogen produced by ethane cracking (810) and an outlet for methaneproduced by ethane cracking (710). The propane dehydrogenation unit (32)may further comprise an outlet for hydrogen produced by propanedehydrogenation (820).

The gas separation unit (50) may further comprise an outlet for butanes(260), wherein said process installation further comprises a butanecracker (34) comprising an inlet for butanes (260) and an outlet forolefins (530) and an outlet for BTX (600). The BTX is preferablycomprised in the pygas produced by said butane cracker (34). This aspectof the present invention is presented in FIG. 3 (FIG. 3). The butanecracker (34) may further comprise an outlet for hydrogen produced bybutane cracking (830) and an outlet for methane produced by butanecracking (730).

In this respect, it is to be noted that the cracked gas produced by thedifferent cracker units may be combined and subjected to a singleseparation section to separate the olefins and BTX comprised in thecracked gas from the other components.

The present invention further provides the use of the processinstallation according to the present invention for converting crude oilinto petrochemical products comprising olefins and BTX.

A further preferred feature of the present invention is that allnon-desired products, such as non-high-value petrochemicals may berecycled to the appropriate unit to convert such a non-desired productto either a desired product (e.g. a high-value petrochemical) or to aproduct that is a suitable as feed to a different unit. This aspect ofthe present invention is presented in FIG. 3 (FIG. 3).

In the process and the process installation of the present invention,all methane produced is collected and preferably subjected to aseparation process to provide fuel gas. Said fuel gas is preferably usedto provide the process heat in the form of hot flue gases produced byburning the fuel gas or by forming steam. Alternatively, the methane canbe subjected to steam reforming to produce hydrogen. Also the undesiredside products produced by e.g. steam cracking may be recycled. Forinstance, the carbon black oil and cracked distillate produced by steamcracking may be recycled to aromatic ring opening.

The different units operated in the process or the process installationof the present invention are furthermore integrated by feeding thehydrogen produced in certain processes, such as in olefins synthesis, asa feedstream to processes that need hydrogen as a feed, such as inhydrocracking. In case the process and the process installation is a netconsumer of hydrogen (i.e. during start-up of the process or the processinstallation or because all hydrogen consuming processes consume morehydrogen than produced by all hydrogen producing processes), reformingof additional methane or fuel gas than the fuel gas produced by theprocess or the process installation of the present invention may berequired.

The following numerical references are used in FIGS. 1-3:

-   10 crude distillation unit-   26 aromatic ring opening unit-   30 unit for olefins synthesis-   31 ethane cracker-   32 propane dehydrogenation unit-   34 butanes cracker-   40 resid upgrading unit, preferably a resid hydrocracker-   50 gas separation unit-   60 fluid catalytic cracking unit-   100 crude oil-   200 LPG produced in the integrated process-   220 gases fraction and refinery unit-derived LPG produced in the    integrated process-   222 LPG produced by aromatic ring opening-   223 LPG produced by resid upgrading-   230 gases fraction-   240 ethane-   250 propane-   260 butanes-   302 hydrocarbon feed to aromatic ring opening-   310 kerosene and/or gasoil, and optionally the naphtha, produced by    crude oil distillation unit-   320 refinery unit-derived middle-distillate and optionally the    refinery unit-derived light-distillate produced the integrated    petrochemical process installation-   324 middle-distillate, and optionally light-distillate, produced by    fluid catalytic cracking-   326 resid upgrading liquid effluent-   327 part of the liquid resid upgrading effluent that is not    subjected to fluid catalytic cracking-   328 light-distillate produced by aromatic ring opening-   400 resid-   401 refinery unit-derived heavy-distillate-   410 heavy-distillate produced by fluid catalytic cracking-   500 olefins-   510 ethylene produced by ethane cracking-   520 propylene produced by propane dehydrogenation unit-   530 C4 olefins produced by butanes cracking-   540 olefins produced by fluid catalytic cracking-   600 BTX-   701 methane produced by gas separation-   710 methane produced by ethane cracking-   720 methane produced by fluid catalytic cracking-   730 methane produced by butanes cracking-   810 hydrogen produced by ethane cracking-   820 hydrogen produced by propane dehydrogenation-   830 hydrogen produced by butanes cracking

Although the invention has been described in detail for purposes ofillustration, it is understood that such detail is solely for thatpurpose and variations can be made therein by those skilled in the artwithout departing from the spirit and scope of the invention as definedin the claims.

It is further noted that the invention relates to all possiblecombinations of features described herein, preferred in particular arethose combinations of features that are present in the claims.

It is noted that the term “comprising” does not exclude the presence ofother elements. However, it is also to be understood that a descriptionon a product comprising certain components also discloses a productconsisting of these components. Similarly, it is also to be understoodthat a description on a process comprising certain steps also disclosesa process consisting of these steps.

The present invention will now be more fully described by the followingnon-limiting Examples.

COMPARATIVE EXAMPLE 1

The experimental data as provided herein were obtained by flowsheetmodelling in Aspen Plus. The steam cracking kinetics were taken intoaccount rigorously (software for steam cracker product slatecalculations). The following steam cracker furnace conditions wereapplied: ethane and propane furnaces: COT (Coil Outlet temperature)=845°C. and steam-to-oil-ratio=0.37, C4-furnaces and liquid furnaces: CoilOutlet temperature=820° C. and Steam-to-oil-ratio=0.37.

For the aromatic ring opening a reaction scheme has been used in whichall aromatic, naphthenic and paraffinic compounds were converted intoLPG. The product slates from propane dehydrogenation were based onliterature data. The resid hydrocracker and the FCC unit were modelledbased on data reported in open literature.

In Comparative Example 1, Arabian light crude oil is distilled in anatmospheric distillation unit. All fractions except the resid are beingsteam cracked. The fractions sent to the steam cracker comprise LPG,naphtha, kerosene and gasoil fractions. The cut point for the resid is350° C. The total fraction of the crude being sent to the steam crackeramounts to 52 wt % of the crude. In the steam cracker the abovementioned crude fractions are being cracked in the furnaces. The resultsare provided in table 1 as provided herein below.

The products that are derived from the crude oil are divided intopetrochemicals (olefins and BTXE, which is an acronym for BTX+ethylbenzene) and other products (hydrogen, methane and heavy fractionscomprising C9 resin feed, cracked distillate, carbon black oil andresid). The total amount sums up to 100% of the total crude, since theresid is also taken into account. From the product slate of the crudeoil the carbon efficiency is determined as:

(Total Carbon Weight in petrochemicals)/(Total Carbon Weight in Crude).

For the Comparative Example the propylene yield is 8 wt-% of the totalcrude.

EXAMPLE 1

Example 1 is identical to the Comparative Example except for thefollowing:

The naphtha, kerosene and gas oil fractions (cut point 350° C.) of thecrude distillation are subjected to aromatic ring opening that isoperated under process conditions to open all aromatic rings and convertthe remaining paraffins and naphthenes into LPG (intermediate). This LPGis separated into an ethane-, propane- and butane fraction. The ethaneand butane fractions are being steam cracked. The propane fraction isdehydrogenated into propylene (with ultimate selectivities of propane topropylene 90%).

Table 1 as provided herein below displays the total product slate fromthe steam cracker (cracked lights and ethane and butane) and from thepropane dehydrogenation unit, in wt-% of the total crude. The table alsocontains the remaining atmospheric residue fraction.

For Example 1 the propylene yield is 29 wt-% of the total crude.

EXAMPLE 2

Example 2 is identical to Example 1 except for the following:

First, the resid is upgraded in a resid hydrocracker to produce gases,light-distillate and middle-distillate. The gases produced by residhydrocracking are steam cracked. The light-distillate andmiddle-distillate produced by resid hydrocracking are subjected toaromatic ring opening that is operated under process conditions to openall aromatic rings and convert the remaining paraffins and naphthenesinto LPG (intermediate). This LPG is separated into an ethane-, propane-and butane fraction. The ethane and butane fractions are steam cracked.The propane fraction is dehydrogenated into propylene (with ultimateselectivities of propane to propylene 90%).

Furthermore, the heavy part of the cracker effluent (C9 resin feed,cracked distillate and carbon black oil) is being recycled to the residhydrocracker. The ultimate conversion in the resid hydrocracker is closeto completion (the pitch of the resid hydrocracker is 2 wt % of thecrude).

Table 1 as provided herein below displays the total product slate of thecrude oil from the steam cracker (cracked products of lights, naphthaand LPG) and from the propane dehydrogenation unit in wt % of the totalcrude. The product slate also contains the pitch of the hydrocracker (2wt % of the crude).

For Example 2 the propylene yield is 55 wt-% of the total crude.

EXAMPLE 3

Example 3 is identical to Example 2 except for the following:

The resid hydrocracker does not crack to extinction but the conversionto gases, light-distillate and middle-distillate fractions is 37.5%. Theremaining product from the resid hydrocracker (heavy distillate andbottom) is sent to a FCC unit, to produce lights and FCC naphtha. Thelights are sent to the steam cracker where the olefins in the lights areseparated from the LPG. This LPG is separated into an ethane-, propane-and butane fraction. The ethane and butane fractions are steam cracked.The propane fraction is dehydrogenated into propylene (with ultimateselectivities of propane to propylene 90%). The FCC naphtha is subjectedto aromatic ring opening under process conditions to open all aromaticrings and convert the remaining paraffins and naphthenes into LPG(intermediate). This LPG is separated into an ethane-, propane- andbutane fraction. The ethane and butane fractions are steam cracked. Thepropane fraction is dehydrogenated into propylene (with ultimateselectivities of propane to propylene 90%). The LCO (light cyclic oil)from the FCC unit is recycled to the resid hydrocracker.

Table 1 as provided herein below displays the total product slate of thecrude oil from the steam cracker (cracked products of lights, naphthaand LPG) and from the propane dehydrogenation unit in wt % of the totalcrude. The product slate also contains the pitch of the hydrocracker andthe coke of the FCC unit (together 4 wt % of the crude).

For example 3 the propylene yield is 51 wt-% of the total crude.

TABLE 1 Comparative Example Example 1 Example 2 Example 3 Petrochemicals(wt-% of crude) Ethylene   15%   15% 29% 27% Propylene   8%   29% 88%51% Butadiene   2%   0%  1%  1% 1-butene   1%   1%  2%  4% Isobutene  1%   0%  1%  2% Isoprene   0%   0%  0%  0% Cyclopentadiene   1%   0% 0%  0% Benzene   4%   0%  1%  1% Toluene   2%   0%  0%  0% Xylene   1%  0%  0%  0% Ethylbenzene   1%   0%  0%  0% Other components (wt-% ofcrude) hydrogen   1%   2%  4%  4% methane   7%   3%  6%  6% Heavy   56%  48%  0%  0% components RHC pitch and   0%   0%  2%  4% FCC coke Carbon38.0% 47.6% 92.5 88.6 efficiency

1. An integrated process to convert crude oil into petrochemicalproducts comprising crude oil distillation, aromatic ring opening andolefins synthesis, which process comprises subjecting a hydrocarbon feedto aromatic ring opening to produce LPG and subjecting the LPG producedin the integrated process to olefins synthesis, wherein said hydrocarbonfeed comprises: kerosene and/or gasoil produced by crude oildistillation in the process; and refinery unit-derived middle-distillateproduced in the process.
 2. The process according to claim 1, whichprocess comprises: (a) subjecting crude oil to crude oil distillation toproduce gases fraction, resid and one or more of kerosene and gasoil;(b) subjecting resid to resid upgrading to produce LPG and a liquidresid upgrading effluent; (c) subjecting liquid resid upgrading effluentand one or more selected from the group consisting of kerosene andgasoil to aromatic ring opening to produce LPG; and (d) subjecting LPGproduced in the integrated process to olefins synthesis.
 3. The processaccording to any one of claim 2, wherein the resid upgrading is residhydrocracking.
 4. The process according to claim 1, wherein at least 50wt-% of the combined kerosene and gasoil produced by the crude oildistillation in the process is subjected to aromatic ring opening. 5.The process according to claim 1, wherein the olefins synthesiscomprises pyrolysis of ethane and dehydrogenation of propane.
 6. Theprocess according to claim 1, wherein the olefins synthesis comprisespyrolysis of butane.
 7. The process according to claim 2, furthercomprising subjecting part of the liquid resid upgrading effluent, andoptionally light-distillate produced by aromatic ring opening, to fluidcatalytic cracking to produce light-distillate, middle-distillate andolefins, and subjecting said middle-distillate produced by fluidcatalytic cracking to aromatic ring opening.
 8. A process installationto convert crude oil into petrochemical products comprising a crudedistillation unit (10) comprising an inlet for crude oil (100) and atleast one outlet for kerosene and/or gasoil (310); an aromatic ringopening unit (26) comprising an inlet for a hydrocarbon feed to aromaticring opening (302) and an outlet for LPG (222); and a unit for olefinssynthesis (30) comprising an inlet for LPG produced by the integratedpetrochemical process installation (200) and an outlet for olefins(500), wherein said hydrocarbon feed to aromatic ring opening comprises:kerosene and/or gasoil produced by the crude oil distillation unit (10);and refinery unit-derived middle-distillate produced the integratedpetrochemical process installation.
 9. The process installationaccording to claim 8, wherein: the crude distillation unit (10)comprises an outlet for gases fraction (230), an outlet for resid (400)and at least one outlet for kerosene and/or and gasoil (310); and aresid upgrading unit (40) comprising an inlet for resid (400) andrefinery unit-derived heavy-distillate (401), an outlet for LPG producedby resid upgrading (223) and outlet for liquid resid upgrading effluent(326).
 10. The process installation according to claim 8, furthercomprising a fluid catalytic cracking unit (60) comprising an inlet fora part of the liquid resid upgrading effluent (326) and optionallylight-distillate produced by aromatic ring opening (328) and an outletfor middle-distillate produced by fluid catalytic cracking (324) andolefins produced by fluid catalytic cracking (540).
 11. The processinstallation according to claim 8, further comprising a gas separationunit (50) comprising an inlet for gases produced in the integratedprocess (200), an outlet for ethane (240) and an outlet for propane(250); an ethane cracker (31) comprising an inlet for ethane (240) andan outlet for ethylene (510); and a propane dehydrogenation unit (32)comprising an inlet for propane (250) and an outlet for propylene (520).12. The process installation according to claim 8, further comprising abutane cracker (34) comprising an inlet for butane (260) and an outletfor olefins (530) and an outlet for BTX (600).
 13. (canceled)